The United Nations is warning of massive population displacements due to military operations and ongoing fighting between rival armed groups in northern Pakistan, near the Afghan border.

Jens Laerke, spokesman for the Office for the Coordination for Humanitarian Affairs, said nearly 76,000 people, or about 13,000 families, have already been displaced since mid-March in the Tirah Valley, in Pakistan's Federally Administered Tribal Areas.

The spokesman said Pakistani government officials say tens of thousands more people may be forced from their homes in the near future because of the situation.

Laerke added that government authorities, UN agencies, and humanitarian groups had been providing basic assistance to the displaced, but estimated that $25 million more in assistance will be needed for the remainder of the year.